This is a prospective, Phase II, open-label, two-arm parallel study evaluating the efficacy and safety of combined treatment (L-Ornithine L-Aspartate, N-Acetylcysteine) with CDK4/6 inhibitors and Fulvestrant in patients with HR-positive/HER2-negative advanced breast cancer (ABC) who have progressed on prior standard therapy including CDK4/6 inhibitors and endocrine therapy.
Women aged ≥ 18 years old.
Patients with histologically confirmed HR+/HER2- invasive breast cancer (specific definition: ER > 10% tumor cell positivity by immunohistochemistry is defined as ER positive, PR positive, PR > 10% tumor cell positivity is defined as PR positive; HER2 0 - 1+ or HER2 ++ but negative by FISH without amplification is defined as HER2 negative).
Patients with HR+/HER2- advanced breast cancer who have experienced disease progression after receiving systemic therapy including CDK4/6 inhibitors and endocrine therapy.
Patients whom the investigator judges to be suitable for continued endocrine therapy
Patients who have received radiotherapy (except for palliative reasons), chemotherapy, immunotherapy, or bisphosphonates (except for bone metastases) within 3 weeks prior to treatment.
Patients with uncontrolled central nervous system metastases (defined as symptomatic or requiring the use of corticosteroids or mannitol to control symptoms).
Patients with a history of clinically important or uncontrolled heart disease, including congestive heart failure, angina pectoris, myocardial infarction within the past 6 months, or ventricular arrhythmia.
Patients with ongoing ARs ≥ Grade 1 due to prior therapy. Exception to this is alopecia or those that, in the opinion of the investigator, should not be excluded. Such cases should be clearly documented in the investigator's notes.